package jiu;

/**
 * Created by mc on 2016/7/29.
 */
import java.util.*;
public class liu
{
    public static void main(String[] arges)
    {
        Set<Integer> numbers = new TreeSet<>();
        numbers.add(1);
        numbers.add(2);
        numbers.add(1);
        numbers.add(2);
        foreach(numbers);
    }
    private static void foreach(Collection<Integer> numbers){
        for(Integer number : numbers){
            System.out.println(number);
        }
    }
}
